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User Guide •
Smartpack S Controller
About Power System Configuration
350030.013, 1v0-2012-06
• Hysteresis and Time delay
When the input signal has reached a certain limit or criteria for a
certain
period of time
, the alarm monitor raises an alarm. This period of time is
called
Time delay
.
You can also enter a
hysteresis
value to prevent the alarm monitor
from unwanted rapid “switching”, when the input signal is around the
limit or criteria.
For example
: A
MajorHigh Limit
is set to 57.00VDC, with a Hysteresis of
0.10VDC and a Time delay of 5 seconds.
An input signal of 57.08VDC lasting 3 seconds will not cause the alarm
monitor to raise an alarm.
The alarm will only be generated when the input signal is over 57.00VDC
for a longer period of time than 5 seconds (the
Time delay
).
The alarm will only be switched off when the input signal is lower than
56.90VDC (the
hysteresis
).
• Monitored Limits and Events
Analogue and numeric alarm monitors
compare the measured input
with from
one to four user-defined values or limits
; two above normal
value (
Major High
and
Minor High
) and two below normal value (
Minor
Low
and
Major Low
). The type and number of internal actions (events)
are usually defined from factory.
Logical alarm monitors
only compare the measured input signal with a
logical state (normally open or close). The user can define the alarm
group that the monitor will activate when the input signal is not in the
normal state.
• Alarm output groups
For each value or limit, you can select
which alarm output group
(AOG)
the alarm monitor will activate in the event the measured input reach-
es the specific limit
• Measured Average Value
The alarm monitor stores all input signal measurements and performs
average calculations every minute. Then, the monitor continuously
displays the
input signal average value
, and the period of time the input
signal has been measured. You can restart the monitor’s average calcu-
lations.
t
Input Signal
Major High Limit
Alarm is
raised
Time
Delay
Hysteresis